+ Reply to Thread
Results 1 to 10 of 10

Thread: knock retard?

  1. #1
    Join Date
    May 2009
    Location
    Plainfield, IL
    Posts
    2,036

    knock retard?

    What is a normal amount of retard *?


    Just cruising at 70 i have between 1 and 2 *....flooring it I'm around 3-4*

    and i saw a max of 8* during driving/cruising/flooring it
    blown transmissions are about as useful as 97% of the guys on this forum

  2. #2
    Join Date
    Apr 2008
    Location
    Birmingham, AL
    Posts
    3,626
    isnt any amount of knock retard bad???
    01 Silverado

  3. #3
    Join Date
    Mar 2007
    Location
    Austin,TX
    Posts
    479
    Quote Originally Posted by mitch cobb racing View Post
    isnt any amount of knock retard bad???
    yes, ultimately you should see 0.0 at all times. When the pcm senses enough knock retard it will start pulling timing to protect the motor.

  4. #4
    Join Date
    May 2009
    Location
    Plainfield, IL
    Posts
    2,036
    Any suggestions? i'm going to throw the stock tune in and see if i still get it.

    i am getting about 22* advance on stock...and about 28* with 'performance' tune. Both on standard gas. I will try running premium again and see if it goes away on performance tune.
    blown transmissions are about as useful as 97% of the guys on this forum

  5. #5
    Join Date
    Mar 2007
    Location
    Austin,TX
    Posts
    479
    IMO 28* on 87 is way too high. I run 28* with full bolts ons, cam, and 93 octane.

  6. #6
    Join Date
    May 2009
    Location
    Plainfield, IL
    Posts
    2,036
    it's a bully power pup...i would assume they would still be on the safe side of the spectrum, that's a big name to have a risky tune.
    blown transmissions are about as useful as 97% of the guys on this forum

  7. #7
    Join Date
    Mar 2007
    Location
    Austin,TX
    Posts
    479
    Quote Originally Posted by oleshifty View Post
    it's a bully power pup...i would assume they would still be on the safe side of the spectrum, that's a big name to have a risky tune.
    I'm not the one with knock retard

  8. #8
    Join Date
    Aug 2008
    Location
    North Texas
    Posts
    12,078
    2* of KR can pull 8* of real timing. Running crap gas with a tune is not smart.

  9. #9
    Join Date
    May 2009
    Location
    Plainfield, IL
    Posts
    2,036
    I've only run bp in mine, normally mid grade, threw the 87 in it last time, cuz i knew the tank would be gone in 3 days due to highway where I won't be on it much.

    I'll have to look into it, I put the stock tune on today, and I was still getting a little KR, not as much, but some. Wonder if something is rattling and causing fake knock.
    blown transmissions are about as useful as 97% of the guys on this forum

  10. #10
    Join Date
    Mar 2003
    Location
    San Antonio, TX
    Posts
    11,038
    KR is NORMAL.

    Meaning that, Every stock vehicle you monitor will have some KR.
    It's the ECM's job to detect any amount of noise that is close to what the knock sensors pickup.
    87oct isn't a good fuel at all for a performance tune.
    The stock calibration on our trucks is typically setup for low grade fuel.
    Even with the conservative factory tune and 87oct, sometimes there's an excessive amount of KR picked up.
    The 07+ trucks are really bad about picking up too much KR. The knock sensors are very sensitive.

    Now whether it's real knock or false knock will determine if it's dangerous.

    You will typically note KR under a light throttle to heavy load transition. Steps can be taken to eliminate this.

    KR may be noticed at max torque/rpm and a heavy load as well.

    KR at wot isn't acceptable, however, you'll still see some KR on a stock tune at wot.

    If you think it's false or real, take the steps required to figure it out.

    To answer your question and your situation with your truck, 28degs of timing is too much for an 87oct tune.
    Run 91/93oct through the system and you'll notice KR will be mostly gone.
    Does that handheld unit come with options to run 87oct , or just one performance tune? If just one, it's probably setup for premium fuel.

    I sounds like you're trying to run a performance tune with 87oct, but can be easily fixed.

    hope this helps,
    allen

+ Reply to Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts